Apparatus for coating lenses including advanced drying techniques

ABSTRACT

A lens coating apparatus is provided. The apparatus includes a mechanical arm configured to receive and maintain lenses in a desired orientation, a loading station configured to receive and maintain the lenses within the enclosed area, and a combined washing and drying station including a spraying mechanism that directs an upward spray toward a bottom surface of the lens, and blowing devices configured to direct air toward the lens after the lens has been washed. The coating apparatus includes a coating station where liquid coating is sprayed toward the bottom surface of the lens and a curing station where the coated lens is exposed to the UV energy radiation. A programmable controller controls the mechanical arm to collect the lens from the loading station without operator intervention, and move along a linear track between the loading station and the combined washing and drying, coating and curing stations.

This application is a continuation-in-part of currently pending U.S.patent application Ser. No. 14/630,598, entitled “Apparatus and Methodfor Coating Lenses,” inventors Andrew Mackinnon et al., filed Feb. 24,2015, the entirety of which is incorporated herein by reference.

BACKGROUND Field

The present disclosure relates generally to coating lenses, and morespecifically to techniques and devices useful in providing coatings toophthalmic lenses, including drying associated therewith.

Background

Ophthalmic lenses made out of organic materials (also called plasticlenses) are currently employed in a variety of eyeglasses, safetygoggles, and the like. Such lenses are very lightweight, fabricated frommaterials such as polycarbonate, and have virtually replaced othermaterials such as glass. However, while modern ophthalmic lenses aredurable and light, a significant issue with plastic ophthalmic lenses isscratch resistance, and for this reason virtually all ophthalmic lensesare coated with a hard coating, frequently a urethane based coating thatis typically reactive to ultraviolet (UV) light.

Certain procedures have been developed that apply hard coatings toophthalmic lenses, but these procedures and systems suffer from twomajor drawbacks: they tend to be labor intensive and/or tend to directair or some other gas toward the lens for drying purposes, both of whichare undesirable. Certain machines have been developed to automate theprocess, but in some instances, particularly with specialty glasses orsmall producers of such lenses, an operator is required to position thelenses, typically on a support that at least partially obscures an edgeor a side of each lens, coat the lenses, reposition the lenses such thatthe region supported is coated, and coat the remaining side of eachlens. The coated lens must be dried in some manner, possibly at multipletimes during the procedure, and air pressure drying is typicallyemployed. The problem with this procedure is that an operator mustperform each of these steps, and they can be time consuming, and lensesoutput per hour can be limited. Further, when repositioning the lenses,the coating can pick up small particles and if the particles dry withinthe coating a lens can be deemed useless. Thus the need to repositionand dry multiple times is potentially problematic and costly.

Further, whether the lenses are positioned manually by an operator or byan automated process, they are dried using a gas, typically air butdifferent types of gases have been employed (oxygen, etc.), expelled inthe direction of the coated lens or lenses for a period of time,resulting in a dry product. Compressed gasses can be problematic,resulting in small particles being blown over the coatings with the gaswhen drying or curing the coating. While compressed gasses can be ofvarying qualities and purities, such gasses are never completely free ofcontaminants, and in some cases can include a significant number ofparticulates. Further, other sources of particles may exist, includingbut not limited to particles generated by pneumatic cylinders, controlvalves, and vacuum generators. With respect to compressed gasses, thecost of compressed gasses tends to correlate with quality, but even thehighest quality compressed gas is not contaminants free. As with therepositioning discussed above, providing gas containing small particlesover coatings can result in such particles sticking to the coatings,which when dried result in an unacceptable lens. Once the coating isdried, it is very difficult or impossible to be removed from theophthalmic lens, and imperfections in eyeglasses and goggles are simplyunacceptable.

Additionally, the friction of blown gasses can generate surface staticelectrical charges, and directing gases toward or across a lens canresult in a small charge being applied to the lens or coated lens, whichmay draw fine particles to the lens. This too is undesirable, and thustechniques other than directing high pressure gasses toward the lens canprovide benefits to the overall lens coating process.

A further issue with the lens coating process is the cycle time forapplying a coating and finishing the entire process. Each of theprocesses associated with coating lenses takes time, and minimizing theamount of time needed for the necessary processes may be beneficial.

A process and/or device that reduces or eliminates ophthalmic lenscoating issues such as necessity for an operator and/or air dryingissues is thus desirable. Further, such a process with less timerequired to complete the process is also desirable.

SUMMARY

According to a first aspect of the present design, there is provided acoating apparatus comprising an enclosed area. The coating apparatuscomprises a mechanical arm configured to receive and maintain a lens ina desired orientation, a loading station comprising a loading platformconfigured to receive the lens and maintain the lens within the enclosedarea, a combined coating and drying station configured to coat the lenswhile the lens is oriented in the desired orientation, wherein thewashing and drying station comprises a spraying mechanism that directsan upward spray toward a bottom surface of the lens, and a plurality ofblowing devices configured to direct air toward the lens after the lenshas been coated, and a programmable controller. The programmablecontroller is configured to control the mechanical arm to move linearlyand collect the lens from the loading station without operator handlingof the lens, and move along a linear track between the loading stationand the combined washing and drying station for a predetermined amountof time.

According to a second aspect of the present design, there is provided alens coating apparatus comprising an enclosed area. The lens coatingapparatus comprises means for washing and drying at least one side of anoptical lens while oriented in a desired orientation, wherein the meansfor washing and drying comprises a spraying mechanism that directs anupward spray toward a bottom surface of the optical lens and a pluralityof blowing devices configured to direct airflow toward the optical lens,means for receiving the optical lens and maintaining the optical lens ina desired orientation, means for controlling position of the opticallens by directing the receiving means along a linear track to facilitatewashing and drying the optical lens, and a hands-free loading stationcomprising a loading platform configured to receive the optical lens andmaintain the optical lens within the enclosed area for collection by thereceiving means, wherein means for controlling position is configured tocontrol the receiving means to move linearly and collect the opticallens from the hands-free loading station without operator handling ofthe optical lens.

According to a third aspect of the present design, there is provided acoating apparatus comprising an enclosed area, the coating apparatuscomprising a mechanical arm configured to receive and maintain a lens ina desired orientation, a loading station comprising a loading platformconfigured to receive the lens and maintain the lens within the enclosedarea, a washing and drying station configured to coat and dry the lenswhile the lens is oriented in the desired orientation, wherein thewashing and drying station comprises, a spraying mechanism that directsan upward spray toward a bottom surface of the lens, and a plurality ofblower arrangements configured to direct airflow toward the lens afterthe lens has been washed, a linear track configured to receive and guidethe mechanical arm in a linear path, and a programmable controllerconfigured to control the mechanical arm to collect the lens from theloading station without operator handling of the lens, move along thelinear track between the loading station and the washing and dryingstation, and expose the lens to the washing and drying station for awashing procedure and a drying procedure.

Various aspects and features of the disclosure are described in furtherdetail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a conceptual overview of the present design;

FIG. 2A is a representation of the mechanical arm employed in thepresent design;

FIG. 2B is a side view of the mechanical arm;

FIG. 3 illustrates an embodiment of the loading (and possibly unloading)station employed in the present design;

FIG. 4A shows an embodiment of the washing station of the presentdesign;

FIG. 4B illustrates an alternative cover that may be employed with thewashing station of the current design;

FIG. 5 illustrates an embodiment of the coating station of the presentdesign;

FIG. 6 is a representation of the drying (and/or curing) stationaccording to the present design;

FIG. 7 is a flowchart of one embodiment of the present design;

FIG. 8 is a photographic representation of a working version of thepresent design including the various stations, the mechanical arm, andthe linear track along which the mechanical arm operates betweenstations;

FIG. 9 is a photographic representation of the device including aninspection light;

FIG. 10 illustrates an inventive drying arrangement employed in thecurrent design;

FIG. 11 shows a sectional side view of a representative blower filterassembly provided in accordance with the present design; and

FIG. 12 illustrates a sectional end view of a representative blowerfilter assembly provided in accordance with the present design.

DETAILED DESCRIPTION

The present design is directed to a system for coating lenses, includingbut not limited to coating ophthalmic lenses with an appropriatecoating, such as a urethane based coating, using a multiple stationmachine that does not dry coated lenses by blowing air or compressed airacross or directly at the lenses. The basic device presented hereinincludes a loading (and unloading) station wherein the lenses are loadedinto a machine having a closed chamber expressly for this purpose, awashing station where the lenses are washed using a high pressure waterjet stream, typically while being spun, a coating station where thelenses are coated, and a drying or curing station wherein the lenses aredried when wet or cured when coated using a heating lamp rather thancompressed air. In one embodiment, all stations are enclosed within anenclosure, such as a HEPA (High Efficiency Pressure Air) pressurizedenclosure, to reduce risk of contamination. Movement of the lensesbetween the various stations occurs using automated and controlledmovement, via a controller such as a PLC, such that once the lenses areloaded and the door to the enclosure closed, the apparatus begins tooperate and no further contact by operator(s) is required. In normaloperation, no further contact by operators is permitted. The presentdesign may be all electric, essentially lubrication free in theprocessing area, where the linear slide mechanisms, spinning assemblies,and other components are free from grease and oil. The end result ofprocessing using the current design is a set of lenses that has beencoated with less risk of contamination by particles or contaminationresulting from external contaminants.

FIG. 1 shows a general conceptual overview of the present design. FromFIG. 1, enclosure 100 includes loading station 101, also calledloading/unloading station, including in this embodiment two stands 101 aand 101 b configured to receive lenses 101 c and 101 d, such asophthalmic optical lenses. An operator opens door 105 and places atleast one lens and in most cases two complimentary lenses on a stand orthe stands, one lens per stand. Mechanical arm 106 is configured to movelinearly between the four stations shown and also up and down on rails107 and 108 to facilitate the cleaning, coating and drying processes.Mechanical arm 106 may select one lens and transport the one lens towashing station 102 wherein the lens is washed in water or othercleaning solution, and the lens may be spun to remove water or cleaningsolution. Mechanical arm 106 is shown with dotted lines in the variouspositions at stations other than loading station 101, and in certaininstances is indicated to have traveled down rails 107 and 108.

The lens may then be transferred by mechanical arm 106 to drying/curingstation 104 where it is dried using, for example, a radiation sourcesuch as an ultraviolet lamp. Drying/curing station 104 is used to dry awet lens and to cure a coated lens, but can be used for either drying orcuring as desired. Separate drying and curing stations may alternatelybe provided. A shutter is shown in FIG. 1 and described in furtherdetail below, and the shutter is opened when radiant energy is requiredfor drying and closed when such radiant energy is not required. The lensmay then be provided to the coating station 103, where the lens issprayed and coated and may be spun while being coated, where spinningtends to facilitate an even coating on the lens. Finally, the lens istransported by the mechanical arm 106 to the drying/curing station 104,also called the UV station, where the coated lens is dried or curedusing UV light. Mechanical arm 106 travels linearly along track 109between the various stations shown.

FIG. 2A provides a more detailed view of the mechanical arm 106. FromFIG. 2A, a suction cup 201 is provided at the bottom of mechanical arm,and suction cup 201 is attached to guard 202 which keeps liquid fromsplashing or being directed upward. Guard 202 or pieces attached toguard 202 are attached to piece 203, which may be a hollow metal tubethat permits gas to pass through and can be spun, thereby spinning bothguard 202 and suction cup 201. Mechanical arm 106 also includes cylinder204, which together with associated equipment, such as a rotatingelement (not shown) inside cylinder 204 and a pressure source, enablesspinning of piece 203 and a suction to be applied to suction cup 201.Thus an air source or other gas source may be attached to or providedwith cylinder 204, a representation of which is shown as gas source 205,and a power source 206 is also provided. In one embodiment, mechanicalarm 106 moves along track 207 and is commanded by controller 208 asdescribed below. Different programs may be provided to move themechanical arm 106. Wheels may be provided to move within track 207, andother necessary elements (counterweights, pistons, actuators,electronics, and so forth) may be provided.

The primary functionality of mechanical arm 106 is to move linearly orin another acceptable manner between the various stations provided,collecting a lens such as by suction by applying a gas such as airthrough line 209 to draw the suction cup and collect the lens.Mechanical arm 106 also has the ability to spin the suction cup 201 byspinning piece 203 and guard 202, and gives the suction cup 201 theability to articulate upward and downward. Devices known in the art thatcan provide these functions (raising, lowering, spinning, etc.) aresufficient.

FIG. 2B presents a side view of mechanical arm 106. Rail 211 is one oftwo rails used to move the mechanical arm components up and down basedon controller commands. In FIG. 2B, a triangular piece 212 is shown thatrepresents a piece having a lower surface that affixes to the cylinder204 and facilitates travel along the rails, such as rail 211. Rotationalelement 213 is shown, configured to provide rotation of the componentsas described. A rear piece 214 is provided that includes wheels or otherappropriate components allowing travel along track 207. Stop 215 isprovided at the bottom of rail 211 and may join the two rails.Electrical and gas/suction connections are not shown in FIG. 2B.

One embodiment of loading station 101 is represented in FIG. 3. Loadingstation 101 includes two pedestals 301 and 302 having holding elements303 and 304, such as cups, suction cups, or flat or curved surfaces,disposed above pedestals or stands 301 and 302, respectively, andpositioned at a given height. The pedestals 301 and 302 may be springloaded. Height can vary depending on circumstances, and any type ofsurface or arrangement that can hold one lens or two lenses at a givenheight is acceptable as a means for maintaining lenses. In certainembodiments, the height can be fixed, while in other embodiments theheight can differ or be adjusted, but the intent is for the mechanicalarm 106 to pick up one or both of the lenses when the lens or lensesis/are at a known height. Two lenses 305 and 306 are shown in FIG. 3.Mechanical devices, such as pistons or similar raising means, may beprovided to raise the height of the lens or lenses, including raisingthe pedestals 301 and/or 302. An operator initially places the lens orlenses in position, i.e. atop holding elements 303 and/or 304, andmechanical arm 106 collects one lens and subjects the lens to theprocesses described herein, and may return the lens to its originalposition when the desired process is complete. Further, an automatedloading method may be employed, i.e. a method where lenses aremechanically distributed on a holding element (or elements) such aselements 303 and 304 without an operator placing the lens(es) on thepedestal(s) manually.

One embodiment of washing station 102 is shown in FIG. 4A. From FIG. 4A,a solution is provided to chamber 401, such as using a nozzle 404, andat the top of washing station 102 is opening 402. Opening 402 is sizedsuch that guard 202 can fit through with little extra space on theperiphery of the guard 202. In this embodiment, a plastic piece 403 isprovided with opening 402 where plastic piece 403 can be removed andreplaced, and in this FIG. 4A the opening 402 is a simple circularopening. The device in this embodiment directs fluid, such as water orwater including other cleaning components, or other appropriate cleaner,to the lens using nozzle 404. When placed in this position, the lens maybe spun and may be cleaned on one side. Chamber 401 is preferablywatertight, and solution may be evacuated through the base of washingstation 102, such as by a drain, or in any other acceptable manner. Morethan one nozzle 404 may be provided, and nozzle 404 and any othernozzles may be provided at different angles or orientations and mayoscillate if desired.

Alternately, a solution container may be provided (not shown in thisview) and the lens submerged or disposed within solution in a chamber.Solution may be provided to washing station 102 in any other acceptableway, such as via an external fluid source connected to the chamber 401.In operation, the guard 202 is typically positioned close to and/orbelow the upper surface of the washing station 102 during the fluidapplication (washing) procedure such that the guard prevents fluid fromleaving the washing station 102.

FIG. 4B illustrates an alternative cover 411 positionable atop washingstation 102, with a circular opening 412 and a channel 413 permittingthe mechanical arm 106 to position the guard, suction cup, and lensbelow the surface of alternative cover 411 through circular opening 413,and enabling mechanical arm 106 to travel along channel 413 such thatthe piece 203 fits through, with guard 202 below the surface ofalternative cover 411. Mechanical arm 106 positions the lens at the farright end of the alternative cover 411 in the orientation shown. Such aconstruct facilitates use of a smaller chamber, such as less than halfthe footprint of the entire washing station, with a relatively low riskof cleaning fluid (e.g. water, deionized water, or distilled or otherpurified water) splashing onto device components or out of the washingstation 102. The nozzle or nozzles providing fluid (distilled water,de-ionized water, etc.) may be grounded, such as via a grounding strap(not shown), to decrease the possibility of a charge building up on thelens. Multiple nozzles may be provided, and they may oscillate,including according to the angular description provided below.

Coating station 103 coats the lens or lenses and one version of coatingstation 103 is shown in FIG. 5. Coating station 103 may include anopening (not shown in this view) sized similarly to the guard 202 ofmechanical arm 106 such that the guard 202 may pass through. Coatingstation 103 may include a spray chamber 501 and may employ sprayingmechanisms at various orientations, shown as nozzle 502 in FIG. 5.Again, more than one nozzle may be employed, each oriented at a desiredangle, and oscillation of the nozzle(s) or stream(s) may be provided.Coating station 103 facilitates the coating of one side of one lens,typically the bottom side or the side facing away from mechanical arm106. In this orientation, spray is emitted upward toward the bottomsurface of lens 503, and the lens may be spun by mechanical arm 106 ifdesired. The upper side of the lens 503 may be sprayed but the top ofthe lens 503 may be obscured by the devices, e.g. suction cup, employedby the mechanical arm 106 to hold the lens. Operation and spraying inthis manner is not intended to omit coating the opposite side of thelens. The lens will typically be placed in one orientation, such asoutside facing down, and then automatically or manually in the otherposition, such as outside facing up, to coat both sides of the lens. Acontainer or reservoir 504 including the coating, typically a coatingused to coat lenses, such as ophthalmic lenses, may be employed withcompression or force selectively applied to the container or reservoir504, thereby applying coating to the nozzle 502 and lens 503. Theprimary function of coating station 103 is to evenly coat as much of thelens 503 as practicable. The lens 503 may be held in place, and excesscoating may drip to and/or be removed from the bottom of the spraychamber 501. The result is one side and at least the edge of lens 503being coated in the desired coating.

Drying/curing station 104 is shown in FIG. 6 and includes an opening 601such that the mechanical arm 106 can lower the guard 202 through withlittle room on the sides. Once inside, the lens may be exposed toradiant energy for drying, typically by ultraviolet light, and in FIG. 6ultraviolet light source 602 is shown. Additionally or alternately, airdrying may be employed, but air drying can introduce unwanted particleson the coated surface, so this is generally less desirable. Drying ofwet lenses, i.e. uncoated lenses that have been washed or exposed to acleaning solution such as water, may occur using a blower (not shown)that draws clean air from a filter, such as a HEPA filter, over the lenssurface(s) in a laminar flow manner. The current design does not director blow onto or across the lens, but if desired such a design may beprovided. When the coating is applied and in need of drying, the presentsystem employs drying/curing station 104 and specifically the UV lightsource 602 to dry the coating on the lens 603. Also shown in FIG. 6 isan open shutter 604 representing a shutter in an open position andclosed shutter 605 representing a shutter in a closed position.Drying/curing station 104 may also include a vent or a fan equipped witha vent (not shown in this view) to dispel and/or circulate air.

As shown in FIG. 1, the mechanical arm 106 is provided with a lineartrack and can run along the track and employ any one of the stations atany given phase of the coating process. The four stations shown may beplaced proximate one another or may be spaced apart, and the mechanicalarm may move between stations, raise and lower the lens, and the variousstations may be employed and operate in a programmed manner. The presentdesign, a coating machine, operates in a sequential mode performing allfunctions described below for one or two loaded lenses. If two lensoperation is selected, the machine performs one lens sequence first,e.g. the left lens sequence, and the second lens sequence thereafter,e.g. right lens sequence.

A work cycle is performed, exposing the lens to three stations: washing,coating and UV curing. Each station is designed to work at a “meanlevel” of operation to maximize its efficiency, wherein the machineplaces the lens' exposed surface within +/−Xmm of the mean level. Inthis manner, knowledge of the position of the lens at any given point isgenerally known and control of the mechanical arm 106 can be relativelyprecise. Additionally, a probe (not shown) may be employed thatdetermines the lens position, may determine lens position based onknowledge of the lens type, and may facilitate positioning the lens at adesired location, i.e. a geometric selected point being located at adesired height within the various stations. If the system hasinformation about the specific type of lens and the probe determines apoint or points on the lens, the system can determine orientation of thelens (facing up or down) as well as locations of other parts of the lens(edge, corner position, highest and lowest positions, etc.) In thismanner, the thickness of the lens is somewhat immaterial in that themechanical arm 106 can be positioned at a desired height such that apoint or points on the lens are positioned at a known height within thesystem.

Each station speed and time values of operation depend on severalfactors including the curvature of the lens (convex vs. concave) and thesurface tension of the lens material. In one embodiment, an operatorplaces the lens on each loading position by hand. The two loadingstations may be spaced using the VCA (Vision Council of America)standard working tray lens center distance allowing optional loadingdirectly from a tray. An automatic loading feed through conveyor can beprovided to enable auto-loading operation in the coating machine.

Operation may begin after the lens is or lenses are loaded and the dooris closed. After door closure and the indication to begin is given by aSTART signal, the machine may secure the door, such as by latching, andthe machine may begin moving the mechanical arm 106 toward the lensposition with a vacuum pump creating suction in the loading pad orsuction cup at the bottom of the mechanical arm 106. The mechanical arm106 may approach a lens at a relatively slow velocity (micro-stepping)until a vacuum signal (lens presence) is detected. The mechanical armstops when it encounters a certain vacuum level, while the controlleracquires the corresponding encoder count, representing the preciseposition of the lens/lens surface and the piece employed, e.g. suctioncup. The encoder count depends on lens curvature, shape and thickness,and the encoder count may be a different value for different lenses.When the overall process is complete, exhaust air from the vacuum pumpis used to eject the lens from the suction cup.

In order to maintain a same or highly similar bottom side surface levelwith respect of each working station throughout the operational cycle,the vertical mechanical arm 106 axis may rely on or use the loadingencoder count to position the lens appropriately at every station of thesequence up to final sequence unloading.

The information related to the lens being coated can be loaded using,for example, an automatic bar code reader, where the code indicates theworking surface shape and side location. The processor in the coatingmachine may rely on a database of information to automatically select acorrect processing “recipe,” where a processing recipe is a set ofspeeds and time values for all stations in the process, i.e. a series ofprocess steps or operations. Alternately, in a case of fully manualoperation without lens data pre-loading, the machine can evaluate lensshape and thickness to avoid operator recipe selection error. Curvaturemay be measured by employing a probe or multiple probes on the topand/or bottom surfaces of the lens, where the probe may be providedthrough suction cup 201 and piece 203, and/or through holding elements303 and 304 and pedestals or stands 301 and 302. The probe or probes maytravel over the lens, providing radii of curvature and thickness valuesthat can determine the lens being employed. However, providing suchprobes, particularly with the suction cup 201 and piece 203, must resultin a design sufficient to maintain the lens through the procedure, i.e.provide sufficient vacuum. Measurement need not be precise, and simplecurvature (concave or convex) may be sufficient to ensure proper coatingapplication and machine operation.

Operation

In one embodiment of operation, before moving out of the loading station101, a bottom surface probe (not shown) may sense the lens to determineits bottom curvature and radius, selecting the corresponding “recipe”for a convex (CX) or concave (CC) surface. An internal center probe maybe located at a known Z ref vertical position below a reference loadingsurface height, where the loading surface is a spring loaded loadingpad. The probe may be a single, relatively inflexible probe or a movableprobe and more than one point on a lens may be scanned. After loading,the vertical smart axis continues moving the lens down by compressingthe loading pad until the probe senses the lens surface. The controller,such as a PLC (programmable logic controller), may determine the shapeand thickness of the lens by comparing the Z encoder Delta countincrease with the Z_ref value according to the following, where Delta Zis the Z (depth) position of the probe, and and Z_Ref is a reference(depth) position, i.e. an expected position of a flat lens:

-   -   If Delta Z>Z_ref then lens shape is CC (concave) and can        interpolate its radius    -   If Delta Z=Z_ref then lens shape is flat    -   Delta Z<Z_ref then lens shape is CX (convex) and can interpolate        its radius

The lens radius calculated value can be used to establish the meansurface Z value in order to properly position the lens through thewashing station 102, coating station 103, and curing or drying/curingstation 104. As noted, the precise surface and/or precise point on thelens may be positioned using the mechanical arm 106 at a desired heightfor optimal processing. As described herein, lens washing may occurbased on lens position, and precise knowledge of the height of the lenssurface may be beneficial in washing the lens, for example.

The system stores the collection height (at the time vacuum isachieved), where collection height is the height at which the lens iscollected by the suction cup. This provides positional data regardingthe outer extremities of the lens face being coated in relation to thesuction cup. A probe or other detection device provided with thepedestal center or mechanism associated with the pedestal enablesdetermination of attributes at or near the center of the lens face beingcoated in relation to the suction cup. By comparing this data, thesystem determines lens orientation (concave or convex) and profile (anapproximation of the prescription contour or outer radius). This datacan be used to adjust the suction cup/lens position during the wash,dry, coat and cure procedures. As an example, the distance between thelens face and the wash nozzle can be consistent throughout theprocedure, regardless of shape or orientation of the lens presented inany given cycle. This information and adjustment can similarly benefitthe consistency of other module processes.

In one embodiment of washing station 102, the mechanical arm 106 placesthe spinning lens over a high pressure water jet stream. The mechanicalarm 106 moves the spinning lens over the nozzle position, where thenozzle in one embodiment provides an oscillating movement to expose theentire surface to the water jet. The water/cleaning fluid nozzlealignment axis may move with a rocking motion to maintain a generallyperpendicular jet stream with respect to the lens surface in accordancewith bottom surface probe data, i.e. moving in accordance with the knownlens curvature.

The mechanical arm 106 moves the lens to curing or drying/curing station104 and the lens is dried by forced convection using the radiant lampgenerated heat while spinning generally at a higher rate than the washand coating spinoff speeds. Exposing the lens to light radiation tendsto increase surface tension and improve the coating ability during thespin coating cycle in the next station.

The coating station 103 performs a two speed spin coating cycle, withcoating provided as described above. Curing station operates using abi-level power shuttered lamp cycle, wherein the lamp is positionedbehind a shutter, and the shutter is opened and closed at desired timesto prevent warm-up delay issues. The machine allows inline working celloperation by implementing an edge handling staging conveyor in aperpendicular through path.

Washing progresses considering the following factors. The surface impactspot size created by the (cleaning fluid/water, such as distilled water)nozzle depending on the water divergence angle and is a function of thedistance from the nozzle to the lens surface. The nozzle may have a verylow divergence angle, such as an angle of five degrees or less, tomaintain spot size within the lens positioning design parameters. Thewash pressure over the surface spot determines the net diameter orimprint on the surface spot, and is also related to the surface velocityand alignment of the water stream relative to the normal direction ofthe surface.

In order to expose all the surface of the lens to the high pressuresmall dot created by the nozzle, the machine may generate a spiralsweeping pattern over the lens by rotating the lens while simultaneouslymoving the piece 203 on mechanical arm 106 with a radial motion over thenozzle from center to edge. The spiral pattern created by combining themotions provides an increasing surface speed with each correspondingradial, i.e. with each X axis Cartesian robot step increment.

Tangential speed, V, is ω*R, where ω is angular speed (spindle speed)and R the radius of the lens at the contact point, where the spindle isa rotating element, such as piece 203. To maintain a uniform spot size,the system creates a constant velocity over the sweeping spiral patternby proportionally reducing the rotational speed of the lens. Thecontroller interpolates the two axes (spindle speed and position)whereby the lens rotational speed is dependent on spindle position.

The lens surface to be washed can be from convex to concave pattern. Thewash nozzle positioning is, in one embodiment, fixed and coplanar withthe spindle axis at the center position. As the lens spindle moves fromcenter to edge, the angle of alignment to the surface normal increasesup to 45 degrees for high base curves. The velocity vector verticalcomponent of the water jet stream decreases in an amount related to thecosine law as 0.707<cosine α<1.00 where α is the angle between water jetand surface normal at the contact point. In order to compensate for thedecrease in the water speed vector, the velocity of the radial motion orX axis may decrease accordingly following the same cosine law. Since thespindle velocity is related to the X axis positioning, the decrease inspindle velocity will also affect a decrease in the change of therotational speed, changing the deceleration of the spindle.

From the foregoing, the present system may enable decreased rotationspeed due to the precise coverage of the washing jets. Fluid, such asdistilled water, directed according to the foregoing angularrelationships decreases the need for high speed rotation, and thuslenses can be rotated at a lower speed than in previous designs.

It is to be understood that lenses may be loaded in one orientation,such as outside down, and proceed through the various stations generallyin this orientation, with the outside of the lens being washed, dried,coated, and cured and potentially returned to the loading station 101.The lenses may then be inverted, such as with the inside down, after theoutside has been cured, and may pass through the various stations suchthat the inside is washed, dried, coated, and cured. Inversion ormovement of the lenses at loading station 101 may be performed by anoperator.

FIG. 7 illustrates a general flowchart of the operation of the presentdesign. At point 701, a lens or pair of lenses is loaded into theloading station 101. Lenses may be loaded in a particular orientation.When ready for operation, the door is closed at point 702, but anothermethod of turning on the device and initiating may be performed. Pointsbelow point 702 are thus performed automatically or without userintervention, and may be programmed as desired, i.e. operating a certainprocess for a desired period of time or at a certain speed. Point 703 isthe removal of the desired lens from the loading station 101 usingmechanical arm 106. Not shown in FIG. 7 is the optional sensing of thelens curvature and/or position using probes, but such a step may occurprior to removing the lens from the loading station 101. Point 703 mayemploy a suction cup or other holding device employed by mechanical arm106 and this may be used to lift the lens as described above. At point704, the mechanical arm moves and transports the lens to wash station102, places the lens into the wash station chamber, and at point 705provides cleaning fluid or water to the exposed side of the lens whilespinning the lens. After a period of time, operation progresses to point706, where the mechanical arm removes the lens from the wash station 102and transports the lens to drying/curing station 104. At point 707, theshutter is opened and UV light energy provided to the washed side of thelens, with the light source directed upward toward the lens. After aperiod of time, at point 708, the UV shutter is closed and the lens isremoved by the mechanical arm 106 from the drying/curing station 104 andtransported to coating station 103 and placed within the coating station103.

At point 709, coating is applied to the lens, typically by an upward jetof coating directed at the lens, typically while the mechanical arm 106is spinning the lens. Coating is applied for a predetermined amount oftime, and at point 710 the mechanical arm 106 removes the coated andspun lens from coating station 103 and transfers it to drying/curingstation 104. At point 711, the system opens the shutter, exposing thecoated lens to radiant energy such as UV light to cure the coating.After a period of time, the lens is removed from the drying/curingstation 104 and may be either maintained and removed by an operator who,for example, opens the door and possibly powers down the system,removing suction from the suction cup at the end of mechanical arm 106or releasing another holding mechanism used to hold the lens, or by themechanical arm 106 by transitioning from the drying/curing station 104to the loading station 101, releasing the lens by relieving the pressureor suction on the suction cup and depositing the coated lens on anappropriate one of the stands/pedestals on the loading/unloading station101. The operator may then open the door or otherwise cease operationand may invert the lens on the pedestal and repeat the process.Alternately, the second lens may be retrieved and processed according toFIG. 7. Note that if desired, once the coated lens has been dried orcured, the lens need not be returned to the loading/unloading station101, but can the processed lens may be held in place such as over one ofthe stations and control may be provided wherein an operator can gainaccess to the enclosure, such as by opening a door, and the pressure orsuction of the mechanical arm released, allowing removal of the lens.

Further, programming may be provided wherein an outside or outer surfaceof a first lens is treated, outside of a second lens treated, and thenthe lenses each inverted, and inside of the first lens treated, andinside of the second lens treated. Other combinations or single desiredlens processing (full processing or specialized processing, such as onlywashing a lens) may occur and may be programmed into the device.

Hence with respect to the individual stations, power and control may beprovided to loading and unloading station 101. If simple pedestals areused without probes, no power is required. If probes or movablepedestals are required, power is required. Wash station 103 requires asource of cleaning fluid or water and power or some type of force toapply the cleaning fluid or water, as well as a drain to remove fluid.Fluid may collect and be removed manually or dumped out, but a drain ispreferable, to a disposal unit or other receptacle for appropriaterecycling or disposal. Coating station 103 may provide the coatingsubstance, which in the case of ophthalmic lenses may be a urethanebased coating that is typically reactive to radiant energy such asultraviolet (UV) light, or some other appropriate coating. Such coatingis typically provided in an appropriate container and pressure applied,such as by using an electric pump, and sprayed through a nozzle towardthe lens. Again, a collection arrangement is employed, which may be adrain or simply manual removal of the excess or used coating from thecoating station 103. Hence coating station 103 requires a source ofcoating, such as a reservoir, power, and a receptacle for collectingexcess coating or a drain, and spraying occurs subject to control by thecontroller. Drying/curing station 104 includes a drying device, such asa radiant source (e.g. an ultraviolet light) requiring a power sourceand a shutter also requiring a power source, and may include a fan orother moving air source. While in certain instances use of compressedair is not desirable, such as when drying a coated lens, compressed airor a fan may be employed to promote circulation of air and a relativeuniformity in the heat being applied by the ultraviolet light source.Other sources of heat may be employed. But electricity and control arepreferably provided to drying/curing station 104.

One alternate embodiment of the present design does not employ airbetween the radiant light source and the lens, but instead employs aquartz plate or quartz grating, screen, or filter between the radiantlight source and the lens. A quartz plate can reduce some of the radiantenergy therefore changing the characteristics of the dry/cure method. Adichroic filter added to a quartz plate and possibly the UV lampreflector enables further manipulation of the dry/cure characteristics.The lens may alternately be dried with the shutter closed, reducing lenstemperature.

In addition to or as an alternative to the shutter mechanism, thepresent design can also include an independently controlled movingwindow mechanism at the drying/curing station 104, which could be movedas needed during either the drying or curing operations. Such a movingwindow mechanism may be provided between the shutter and the lens, suchas above elements 604 and 605 in FIG. 6, and may in certain instancesprovide improved control over lens temperature and preparation forcoating.

One embodiment of the current design is shown in FIG. 8, includingloading station 101, washing station 102, coating station 103,drying/curing station 104, and mechanical arm 106 which moves along thetrack on command by the controller between the various stations. Thevarious stations are contained within an enclosure, and in this view nodoor is shown but one is typically provided. Exposure to the variousstations may be any amount of time and may be for a predetermined timevalue, from seconds to tens of seconds and even longer in somesituations.

Additional features may be provided as desired. One such additionalfeature is an inspection light 901, shown in FIG. 9, added to theloading station proximate the loading door in this embodiment. Theinspection light 901 enables an operator to visually inspect a lens ormultiple lenses for defects before, during, or after processing whilethe lens or lenses remain inside the clean environment, such as anenvironment including HEPA filtered air. Electrical power must beprovided to such a light, and any type of necessary connection foradditional equipment must be provided (e.g. power, fluid, control, etc.)

Control may be provided by a controller having a visual interface,enabling the user to select a program having a sequence of steps or insome cases allowing the user to select his or her own functions to beperformed. The controller may include a user interface with atouchscreen or buttons, and any programmable logic controller able toprovide the functionality called for herein may be employed. Userselection may be employed but is optional, and the controller has theability to issue commands facilitating the transition between stationssuggested by, for example, the functions called out in FIG. 7.

Another way of describing operation of the design is as follows. Anoperator opens a load door and loads a pair of lenses onto two springloaded pedestals. When the door is closed, the operator selects theappropriate process program and starts the processing cycle. Theapparatus automatically moves a vacuum cup over the lens and picks it up(in a pick-and-place type operation). The lens is transferred into awashing bowl for cleaning and is sprayed with filtered water (distilledor deionized water). The device spins the lens to remove most of thewater. The lens is transferred to a UV station and may be positioned infront of a blower. A UV or other radiant lamp provides radiation (UV,infrared, etc.) to facilitate the drying process. The lens is spunduring drying. The device transfers the lens to a coating station whereit is spun and sprayed with coating. The spinning process provides aneven coating film. The lens is then transferred to the UV station whereit is cured. The lens is returned to the pedestal and the machine willeither process the next lens, or finish the cycle.

Enhanced Drying

FIG. 10 illustrates an enhanced attribute of the present design. Thedrying process, using ultraviolet heating, may take significant timedepending on various factors, ambient temperature and humidity, and soforth. An alternative drying embodiment is shown in FIG. 10, wherein thealternate drying embodiment comprises two blowers on the underside ofthe wash station, at the opposite side of the wash nozzle. This reducesthe number of transferences between stations, and once the lens has beenwashed, drying can be initiated using the blower arrangement disclosed.From FIG. 10, station 1001 includes wash bowl 1002, constructed toinclude an angled portion to receive wash and debris, with two blowerassemblies including lower blower assembly 1003 and side blower assembly1004. In this view, lens 1005 is provided on a lens receiving device,such as a rubber suction device 1006 with a guard 1007 attached to acentral shaft 1008.

FIG. 11 shows an expanded version of the blower arrangement in crosssection, and more specifically, a sectional side view of arepresentative blower assembly. Blower arrangement designs similar oridentical to, or even different from the blower arrangement 1100 shownin FIG. 11 may be employed as the lower blower assembly 1003 and sideblower assembly 1004 shown in FIG. 10. From FIG. 11, airflow may bereceived at blower 1101 which has a prefilter 1102 to filter outimpurities received in the airflow. Air may be directed through a nozzle1103 within a filter chamber 1104, wherein the concept is to force airinto the filter chamber and out the outlet tube 1105. Within the filterchamber 1104 is a cylindrical filter 1106 pressure provided via theblower nozzle 1103 to the chamber is forced through the cylindricalfilter 1106 into the interior portion of the cylindrical filter 1106used to further filter the air received and such air within thecylindrical filter 1106 is forced through air outlet tube 1105. The lensis spun and may be repositioned, such as lowered slightly to improve aircoverage over a variety of lens profiles.

FIG. 12 illustrates a sectional end view of a representative blowerfilter assembly. From FIG. 12, airflow is received at prefilter 1102 andprovided to blower 1101, having attached thereto blower motor 1201. Airis directed, according to the arrows provided, from blower 1101 tofilter chamber 1104 in which is positioned cylindrical filter 1106. Aircirculates around cylindrical filter 1106 and passes through cylindricalfilter 1106 and out of air outlet tube 1105.

Such a construction, using blower motors or blower arrangements similarto those shown, enables the bypassing of the UV or drying stationcompletely. In other words, the drying station may be removed or omittedin its entirety. The result is a more compact system and more rapiddrying of lenses, which is beneficial overall.

The present design thus includes a coating apparatus comprising amechanical arm configured to receive and maintain a lens in a desiredorientation, a coating station configured to coat the lens, an optionaldrying station configured to dry the lens using radiant energy, and aprogrammable controller configured to control the mechanical arm to movealong a linear track between the coating station and drying station andexpose the lens to the coating station for a coating procedure and thedrying station for a drying procedure for a predetermined amount oftime. Other stations may be provided, such as a washing station and aloading station.

Additionally, the present design comprises a lens coating apparatuscomprising means for coating at least one side of an optical lens,optional means for drying/curing the optical lens using radiant energy,means for receiving the optical lens and maintaining the optical lens ina desired orientation, and means for controlling position of the opticallens by directing the receiving means along a linear track to facilitatecoating the optical lens using the coating means and drying the opticallens using the drying means.

According to a further embodiment of the present design, there isprovided a method for processing an optical lens. The method includesreceiving and maintaining the optical lens using a mechanical armconfigured to maintain the optical lens in a desired orientation,directing the mechanical arm maintaining the optical lens to an opticallens coating position and coating at least one side of the optical lens,and optionally directing the mechanical arm maintaining the optical lensto an optical lens drying/curing position and drying the optical lensusing radiant energy. The mechanical arm is controlled to move along alinear track between the optical lens coating position and the opticallens drying/curing position.

According to an alternate embodiment of the present design, there isprovided a coating apparatus comprising an enclosed area. The coatingapparatus comprises a mechanical arm configured to receive and maintaina lens in a desired orientation, a loading station comprising a loadingplatform configured to receive the lens and maintain the lens within theenclosed area, a combined coating and drying station configured to coatthe lens while the lens is oriented in the desired orientation, whereinthe coating and drying station comprises a spraying mechanism thatdirects an upward spray toward a bottom surface of the lens, and aplurality of blowing devices configured to direct air toward the lensafter the lens has been coated, and a programmable controller. Theprogrammable controller is configured to control the mechanical arm tomove linearly and collect the lens from the loading station withoutoperator handling of the lens, and move along a linear track between theloading station and the combined coating and drying station for apredetermined amount of time.

According to a further aspect of the present design, there is provided alens coating apparatus comprising an enclosed area. The lens coatingapparatus comprises means for coating and drying at least one side of anoptical lens while oriented in a desired orientation, wherein the meansfor coating and drying comprises a spraying mechanism that directs anupward spray toward a bottom surface of the optical lens and a pluralityof blowing devices configured to direct airflow toward the optical lens,means for receiving the optical lens and maintaining the optical lens ina desired orientation, means for controlling position of the opticallens by directing the receiving means along a linear track to facilitatecoating and drying the optical lens, and a hands-free loading stationcomprising a loading platform configured to receive the optical lens andmaintain the optical lens within the enclosed area for collection by thereceiving means, wherein means for controlling position is configured tocontrol the receiving means to move linearly and collect the opticallens from the hands-free loading station without operator handling ofthe optical lens.

According to another aspect of the present design, there is provided acoating apparatus comprising an enclosed area, the coating apparatuscomprising a mechanical arm configured to receive and maintain a lens ina desired orientation, a loading station comprising a loading platformconfigured to receive the lens and maintain the lens within the enclosedarea, a washing and drying station configured to coat and dry the lenswhile the lens is oriented in the desired orientation, wherein thewashing and drying station comprises, a spraying mechanism that directsan upward spray toward a bottom surface of the lens, and a plurality ofblower arrangements configured to direct airflow toward the lens afterthe lens has been coated, a linear track configured to receive and guidethe mechanical arm in a linear path, and a programmable controllerconfigured to control the mechanical arm to collect the lens from theloading station without operator handling of the lens, move along thelinear track between the loading station and the washing and dryingstation, and expose the lens to the washing and drying station for acoating procedure and a drying procedure.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the scope of thedisclosure. Thus, the disclosure is not intended to be limited to theexamples and designs described herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A coating apparatus comprising an enclosed area,the coating apparatus comprising: a mechanical arm configured to receiveand maintain a lens in a desired orientation; a loading stationcomprising a loading platform configured to receive the lens andmaintain the lens within the enclosed area; a combined washing anddrying station configured to wash the lens while the lens is oriented inthe desired orientation, wherein the washing and drying stationcomprises a spraying mechanism that directs an upward spray toward abottom surface of the lens, and a plurality of blowing devicesconfigured to direct air toward the lens after the lens has been coated;and a programmable controller configured to control the mechanical armto: move linearly and collect the lens from the loading station withoutoperator handling of the lens; and move along a linear track between theloading station and the combined washing and drying station for apredetermined amount of time.
 2. The coating apparatus of claim 1,further comprising a coating station, wherein the programmablecontroller is further configured to control the mechanical arm to movealong the linear track between the coating station and the combinedwashing and drying station and expose the lens to the coating stationfor a coating procedure for a further amount of time.
 3. The coatingapparatus of claim 2, wherein the programmable controller is furtherconfigured to move along the linear track between the loading station,the coating station, and the combined washing and drying station.
 4. Thecoating apparatus of claim 1, wherein the plurality of blowing devicescomprise at least one blowing station comprising an air filter.
 5. Thecoating apparatus of claim 3, wherein the loading station comprises aprobe employed with the programmable controller to sense an attribute ofthe lens while positioned at the loading station within the enclosedarea, wherein the attribute of the lens comprises at least one from thegroup consisting of lens position, lens curvature, and lens thickness.6. The coating apparatus of claim 5, further wherein the probe isconfigured to operate with the programmable controller to determine alowest point on the lens and maintain the lowest point on the lens at adesired height in the coating station, and the combined washing anddrying station.
 7. The coating apparatus of claim 1, wherein themechanical arm comprises a suction cup configured to maintain the lens.8. The coating apparatus of claim 1, wherein the mechanical armcomprises an element configured to spin the lens while providing thelens to the combined coating and drying station.
 9. A lens coatingapparatus comprising an enclosed area, the lens coating apparatuscomprising: means for washing and drying at least one side of an opticallens while oriented in a desired orientation by directing an upwardspray from a spraying mechanism toward a bottom surface of the opticallens and directing airflow from a plurality of blowing devices towardthe optical lens; means for receiving the optical lens and maintainingthe optical lens in a desired orientation; means for controllingposition of the optical lens by directing the means for receiving alonga linear track to facilitate washing and drying the optical lens; and ahands-free loading station comprising a loading platform configured toreceive the optical lens and maintain the optical lens within theenclosed area for collection by the means for receiving, wherein themeans for controlling position is configured to control the means forreceiving to move linearly and collect the optical lens from thehands-free loading station without operator handling of the opticallens.
 10. The lens coating apparatus of claim 9, further comprisingmeans for washing the lens, wherein the means for controlling positionof the optical lens is further configured to direct the receiving meansalong the linear track between the means for coating and the means forwashing and drying.
 11. The lens coating apparatus of claim 10, whereinthe means for controlling position of the optical lens is furtherconfigured to move along the linear track between the hands-free loadingstation, the means for coating, and the means for washing and drying.12. The lens coating apparatus of claim 11, wherein the hands-freeloading station comprises a probe configured to enable sensing of anattribute of the optical lens while positioned at the hands-free loadingstation.
 13. The lens coating apparatus of claim 9, wherein the opticallens comprises an ophthalmic lens.
 14. The lens coating apparatus ofclaim 9, wherein the means for receiving comprises a suction cupconfigured to maintain the lens.
 15. The lens coating apparatus of claim9, wherein the means for receiving is configured to spin the opticallens while providing the optical lens to the means for washing anddrying.
 16. The lens coating apparatus of claim 9, wherein the means forwashing and drying comprises an internal air filter.
 17. A coatingapparatus comprising an enclosed area, the coating apparatus comprising:a mechanical arm configured to receive and maintain a lens in a desiredorientation; a loading station comprising a loading platform configuredto receive the lens and maintain the lens within the enclosed area; awashing and drying station configured to wash and dry the lens while thelens is oriented in the desired orientation, wherein the washing anddrying station comprises: a spraying mechanism that directs an upwardspray toward a bottom surface of the lens; a plurality of blowerarrangements configured to direct airflow toward the lens after the lenshas been coated; a linear track configured to receive and guide themechanical arm in a linear path; and a programmable controllerconfigured to control the mechanical arm to: collect the lens from theloading station without operator handling of the lens; move along thelinear track between the loading station and the washing and dryingstation; and expose the lens to the coating and curing station for acoating procedure and a curing procedure.
 18. The coating apparatus ofclaim 17, further comprising a washing station, wherein the programmablecontroller is further configured to control the mechanical arm to movealong the linear track between the washing station and the coating anddrying and curing station and expose the lens to the washing station fora washing procedure.
 19. The coating apparatus of claim 18, wherein theprogrammable controller is further configured to control the mechanicalarm to collect the lens from the loading station and move along thelinear track between the loading station, washing station, and thecoating and curing station.
 20. The coating apparatus of claim 19,wherein the plurality of blower arrangements comprises at least one airfiltering element.